PHOTODETECTING DEVICE

• Main Authors: YOICHI ENOMOTO, TOSHIAKI MURAKAMI, MINORU SUZUKI
• Format: Patent
• Language: English
• Published: 05.11.1986
• Edition: 4
• Subjects: COLORIMETRY; ELECTRICITY; MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT,POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED,VISIBLE OR ULTRA-VIOLET LIGHT; MEASURING; PHYSICS; RADIATION PYROMETRY; TESTING

A photodetecting device having Josephson junctions, comprises an insulating substrate, a polycrystalline superconductor film formed on the insulating substrate such that Josephson junctions are formed at grain boundaries, the superconductor film having a first region subjected to light illumination, and second and third regions formed contiguously at both sides of the first region such that a width of each of the second and third regions is wider than that of the first region, a bias circuit for supplying a predetermined bias current between the second and third regions, and an output circuit for detecting a change in voltage between the second and third regions, one terminal of said bias circuit and one terminal of said output circuit being commonly grounded, wherein the superconductor film comprises BaPb1-xBixO3 (where 0.05</=x<0.32) having an I-V characteristic of weak link type under temperature condition less than transition temperature of said BaPb1-xBixO3. This simple photodetecting device can detect an optical signal at high speed with high sensitivity.